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Sputtering of niobium by energetic neutrons and protons: a round-robin experiment
Classified abstracts 35003511 indicate that such a system is capable to produce oxide films with satisfactory homogeneity on areas exceeding 1 cm2 and, moreover, the oxidation proceeds over a wide range of oxygen pressures. In the present paper a theoretical model of the Si02 thin tilm growth kinetics on Si substrates in a microwave induced oxygen plasma is given. (Czechoslovakia) R Dragila et al, P/ryr Status Solidi (a), 35 (I), 1976, 291-301. 31 3500. Studies on Al-insulator-Pb tunnel junctions with barriers prepared in glow discharge of CO2 and CO. (Germany) Al-insulator-Pb tunnel junctions with barriers produced in a glow discharge of COZ or CO studied. The glow discharge deposition chamber with an ultimate pressure of less than 1 x lo-* torr was filled with CO or CO1 to a pressure of 2 x 10-z torr. It is shown that the barrier prepared in CO, is similar in its composition to that prepared using the plasma oxidation technique. (USSR) 0 I Shklyarevskiy et al, Phys Stafus Solidi (a), 35 (l), 1976, 49-53. 32. EVACUATION
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32 3501. Three-wavelength helium-neon laser. (USSR) A small-size gas laser is described, in which the generated wavelength changes from 3.3922 to 3.3912 and from 0.6338 to 0.6328 pm by variations of CH4 pressure in the range of 2 x lo-’ to 760 torr in the inner absorption cell. The laser is filled with helium-neon mixture at a pressure of 1.5 torr. V A Balakin et al, Prib Tekh Eksper, No 1, 1976. 165-166 (in Russian). 32 3502. Investigation and improvement of characteristics of channel electron multipliers. (USSR) Characteristics of detection of electrons with energies ranging from 10 to 100 keV by channel electron multipliers are investigated. It is experimentally shown that utilization of an additional transmission stage with free porous CsI film considerably improves the dependence of the output signal on the position of primary electron incidence with respect to the channeltron input funnel axis. S S Kozlovskiy et al, Prib T&h Eksper, No 1, 1976, 162-163 (in Russian). 32 3503. Some results of experimental investigation of caesium-barium fully controlled switch. (USSR) Results of experimental investigation of caesium-barium fully controlled switch with planparallel electrodes are presented. A molybdenum grid is placed between tungsten cathode and molybdenum anode. The barium vapour pressure was varied between lo-’ to 10m3 torr and that of caesium vapour between low4 and 10-Z torr. A L Barannikov et al, Zh Tekh Fiz, 46 (6), 1976, 1358-1360 (in Russian).
33 3505. Resonant optical schlieren system for plasma flow studies. (USA) A dye laser, pumped by ruby second harmonic radiation at 3471 A, emitting -5 mJ, 20 ns pulses with a bandwidth of 0.3 A, has been developed as a light source in a schlieren optical system which utilizes enhanced refractivity to examine plasma flow phenomena. When the dye laser is tuned adjacent to the Ba II ion resonance line at 4554 A, the sensitivity of the system to density gradients in a barium plasma becomes 100-1000 times greater than can be achieved with nonresonant light sources which rely on the free electron contributions to plasma refractivity. Absorption effects also yield data on plasma flow patterns. H J Siebeneck et al, Rev Scient Instrum, 48 (8), 1977,997-1001. 33 3506. investigation of the influence of magnetic pressure on operation of caesium thermionic energy converters. (USSR) The fall of static caesium.vapour pressure is measured at various regimes of operation of a cylindrical thermionic energy converter. The base pressure of the examined converter was lo-’ torr and the caesium vapour pressure in the reservoir ranged from 10-i to 10 torr. V A Druzhinin et al, Zh Tekh Fiz, 46 (6), 1976, 1289-1294 (in Russian). 33 3507. Acoustic converter for measurement of intensity of pulsed beams of charged particles. (USSR) An acoustic converter for measurement of intensity of pulsed beams of charged particles is investigated. It consists of a metal plate with matched piezoelectric ceramic sensor. The sensitivity of the examined converter was 10’ particles per pulse using beams of 800 and 1200 MeV electrons. V I Artemov et al, Zh Tekh Fiz, 46 (6), 1976, 1327-1331 (in Russiun). 3508. A device for ion irradiation of a low-temperature A device is described which enables one to irradiate to 77 K with heavy ions accelerated in a cyclotron. after irradiation can be investigated in a cryostat in interval of 4.2 to 300 K without their heating. V I Pogodin et al, Prib Tekh Eksper, No 2, 1976.26-28
target. (USSZ a target cooled The specimens the temperature (in Russian).
33 3509. A device with power relativistic electron beam of microsecond duration for generation of ultrahigh frequency pulses. (USSR) A device for generation of high-current relativistic electron beams with current up to 3 kA, energy up to 270 keV and pulse duration of 1 ms is described. An electron gun with cold cathode of magnetron type is used as a source of electrons. The cathodes of stainless steel possess the highest stability of tested materials. Generation of ultrahigh frequency power at injection of the beam in a space-periodic magnetic field is also investigated. Yu V Tkach et al, Prib Tekh Eksper, No 2, 1976, 129-l 31 (in Russian).
33. NUCLEONICS 33 3504. Sputtering of niobium by energetic neutrons and protons: a round-robin experiment. (USA) This paper presents the results of a round-robin neutron-sputtering experiment in which six independent research groups have participated. Targets of cold-rolled niobium prepared by two standard techniques were used by all participants. Three participating groups used (d, I) neutrons of about 14.8 MeV, one group used (d, Be) neutrons produced by 40 MeV deutrons on a thick Be target, and two groups used 16 MeV protons in transmission. The emission of micrometer-sized particles was observed by two groups and not observed by the other four. This particle emission was observed by two of the groups who used (d, I) neutrons in their irradiations. Chunk emission was observed for only one of the two standardized target types used in the round-robin. The round-robin results support the concept that the neutron-sputtering yield of Nb, including atomic and chunk emission, has an estimated probable value no larger than 10s4 atoms per neutron. However, sputtering yields in therange 1.4 x 10s5 to 52.6 x lo-” arereported here. The probable value for the sputtering yield was found to be independent of the two target preparations and the method of analysis, whether or not chunks were observed during analysis. R Behrisch et al,JApplPhys, 48 (9), 1977,3914-3918.
34, ELECTRONIC TECHNOLOGY
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34 3510. The damping capability of flexible foam under atmospheric pressure and vacuum by impulse loading. (Germany) Thedampingcapability, the maximum deceleration of the falling mass and the deepest penetration are investigated on polyether and polyester flexible foam with open cells. In order to vary the experimental conditions different kinds of foam are combined and hard intermediate layers are used. As comparable characteric values the reflexion amplitude and the deceleration of the falling body are used. The experimental set-up is designed to allow measurements also under the vacuum down to p - IO Pa (10-I mbar). The maximum free falling distance is 3.6 m, the maximum mass 4.4 kg. Von W Hallmann, Vakuum-Tech, 26 (5), 1977, 130-136 (in German). 34 3511. Production of H-atom and O-atom beams by a cooled microwave diiharge source. (USA) A beam of hydrogen and oxygen atoms in the thermal energy range was produced by microwave discharge. The microwave apparatus was used inside a vacuum chamber and therefore required a cooling 157
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SEALING
32 3501. Three-wavelength helium-neon laser. (USSR) A small-size gas laser is described, in which the generated wavelength changes from 3.3922 to 3.3912 and from 0.6338 to 0.6328 pm by variations of CH4 pressure in the range of 2 x lo-’ to 760 torr in the inner absorption cell. The laser is filled with helium-neon mixture at a pressure of 1.5 torr. V A Balakin et al, Prib Tekh Eksper, No 1, 1976. 165-166 (in Russian). 32 3502. Investigation and improvement of characteristics of channel electron multipliers. (USSR) Characteristics of detection of electrons with energies ranging from 10 to 100 keV by channel electron multipliers are investigated. It is experimentally shown that utilization of an additional transmission stage with free porous CsI film considerably improves the dependence of the output signal on the position of primary electron incidence with respect to the channeltron input funnel axis. S S Kozlovskiy et al, Prib T&h Eksper, No 1, 1976, 162-163 (in Russian). 32 3503. Some results of experimental investigation of caesium-barium fully controlled switch. (USSR) Results of experimental investigation of caesium-barium fully controlled switch with planparallel electrodes are presented. A molybdenum grid is placed between tungsten cathode and molybdenum anode. The barium vapour pressure was varied between lo-’ to 10m3 torr and that of caesium vapour between low4 and 10-Z torr. A L Barannikov et al, Zh Tekh Fiz, 46 (6), 1976, 1358-1360 (in Russian).
33 3505. Resonant optical schlieren system for plasma flow studies. (USA) A dye laser, pumped by ruby second harmonic radiation at 3471 A, emitting -5 mJ, 20 ns pulses with a bandwidth of 0.3 A, has been developed as a light source in a schlieren optical system which utilizes enhanced refractivity to examine plasma flow phenomena. When the dye laser is tuned adjacent to the Ba II ion resonance line at 4554 A, the sensitivity of the system to density gradients in a barium plasma becomes 100-1000 times greater than can be achieved with nonresonant light sources which rely on the free electron contributions to plasma refractivity. Absorption effects also yield data on plasma flow patterns. H J Siebeneck et al, Rev Scient Instrum, 48 (8), 1977,997-1001. 33 3506. investigation of the influence of magnetic pressure on operation of caesium thermionic energy converters. (USSR) The fall of static caesium.vapour pressure is measured at various regimes of operation of a cylindrical thermionic energy converter. The base pressure of the examined converter was lo-’ torr and the caesium vapour pressure in the reservoir ranged from 10-i to 10 torr. V A Druzhinin et al, Zh Tekh Fiz, 46 (6), 1976, 1289-1294 (in Russian). 33 3507. Acoustic converter for measurement of intensity of pulsed beams of charged particles. (USSR) An acoustic converter for measurement of intensity of pulsed beams of charged particles is investigated. It consists of a metal plate with matched piezoelectric ceramic sensor. The sensitivity of the examined converter was 10’ particles per pulse using beams of 800 and 1200 MeV electrons. V I Artemov et al, Zh Tekh Fiz, 46 (6), 1976, 1327-1331 (in Russiun). 3508. A device for ion irradiation of a low-temperature A device is described which enables one to irradiate to 77 K with heavy ions accelerated in a cyclotron. after irradiation can be investigated in a cryostat in interval of 4.2 to 300 K without their heating. V I Pogodin et al, Prib Tekh Eksper, No 2, 1976.26-28
target. (USSZ a target cooled The specimens the temperature (in Russian).
33 3509. A device with power relativistic electron beam of microsecond duration for generation of ultrahigh frequency pulses. (USSR) A device for generation of high-current relativistic electron beams with current up to 3 kA, energy up to 270 keV and pulse duration of 1 ms is described. An electron gun with cold cathode of magnetron type is used as a source of electrons. The cathodes of stainless steel possess the highest stability of tested materials. Generation of ultrahigh frequency power at injection of the beam in a space-periodic magnetic field is also investigated. Yu V Tkach et al, Prib Tekh Eksper, No 2, 1976, 129-l 31 (in Russian).
33. NUCLEONICS 33 3504. Sputtering of niobium by energetic neutrons and protons: a round-robin experiment. (USA) This paper presents the results of a round-robin neutron-sputtering experiment in which six independent research groups have participated. Targets of cold-rolled niobium prepared by two standard techniques were used by all participants. Three participating groups used (d, I) neutrons of about 14.8 MeV, one group used (d, Be) neutrons produced by 40 MeV deutrons on a thick Be target, and two groups used 16 MeV protons in transmission. The emission of micrometer-sized particles was observed by two groups and not observed by the other four. This particle emission was observed by two of the groups who used (d, I) neutrons in their irradiations. Chunk emission was observed for only one of the two standardized target types used in the round-robin. The round-robin results support the concept that the neutron-sputtering yield of Nb, including atomic and chunk emission, has an estimated probable value no larger than 10s4 atoms per neutron. However, sputtering yields in therange 1.4 x 10s5 to 52.6 x lo-” arereported here. The probable value for the sputtering yield was found to be independent of the two target preparations and the method of analysis, whether or not chunks were observed during analysis. R Behrisch et al,JApplPhys, 48 (9), 1977,3914-3918.
34, ELECTRONIC TECHNOLOGY
AND
HIGH
ALTITUDE
PHYSICS
AND
34 3510. The damping capability of flexible foam under atmospheric pressure and vacuum by impulse loading. (Germany) Thedampingcapability, the maximum deceleration of the falling mass and the deepest penetration are investigated on polyether and polyester flexible foam with open cells. In order to vary the experimental conditions different kinds of foam are combined and hard intermediate layers are used. As comparable characteric values the reflexion amplitude and the deceleration of the falling body are used. The experimental set-up is designed to allow measurements also under the vacuum down to p - IO Pa (10-I mbar). The maximum free falling distance is 3.6 m, the maximum mass 4.4 kg. Von W Hallmann, Vakuum-Tech, 26 (5), 1977, 130-136 (in German). 34 3511. Production of H-atom and O-atom beams by a cooled microwave diiharge source. (USA) A beam of hydrogen and oxygen atoms in the thermal energy range was produced by microwave discharge. The microwave apparatus was used inside a vacuum chamber and therefore required a cooling 157